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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Enhancing the monitoring and trapping of protected crop pests by incorporating LED technology into existing traps

McCormack, Kevin January 2016 (has links)
Management of pest species is ordinarily required in the production of protected crops. Integrated pest management (IPM) is commonly used when controlling insects. The European Union Sustainable Use Directives states that "integrated pest management’ means careful consideration of all available plant protection methods and subsequent integration of appropriate measures that discourage the development of populations of harmful organisms and keep the use of plant protection products and other forms of intervention to levels that are economically and ecologically justified and reduce or minimise risks to human health and the environment. ‘Integrated pest management’ emphasises the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms.” Effectively monitoring pests is a key component of IPM, with decisions to use biological control agents (BCA) and insecticides often based on the presence of pests in traps. A commonly used monitoring tool is the sticky trap; these traps are coloured and rely primarily on their visual attractiveness to the pest. The capture efficiency of sticky traps can potentially be increased with the addition of light emitting diodes (LEDs). The objective of this project was to use LEDs to enhance the efficacy of yellow sticky traps for trapping a range of insect pests, to enable more effective timing of pest management by optimising pest monitoring. The addition of LEDs may also enable more effective mass trapping via yellow sticky traps, and minimize the trapping of beneficial insects. Comparisons between standard yellow sticky traps and those equipped with green (540 nm) or blue (480 nm) LEDs were carried out at four commercial growing facilities. Green (540 nm) LED equipped traps were compared with standard yellow traps in a mass release of the biological control agent Encarsia formosa Gahan (Hymenoptera: Aphelinidae), to determine if there are negative consequences to the addition of green (540 nm) LEDs when using this biological control agent. Relative spectral preferences of western flower thrips (Frankliniella occidentalis Pergande (Thysanoptera: Thripidea)) and Glasshouse whitefly (Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae)) were determined using a choice test comparing a range of wavelengths in 20 nm steps against a control wavelength. Green (540 nm), and blue (480 nm) LED equipped traps captured significantly more dark-winged fungus gnats (Bradysia difformis Frey (Sciaridae: Diptera)) and diamondback moths (Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae)) than those without. No significant differences were found between green (540 nm) LED equipped traps and those without for E. formosa, and a significant decrease in the capture of the shore fly parasitoid Kleidotoma psiloides Westwood (Hymenoptera: Figitidae) was observed. In behavioural experiments F. occidentalis showed a peak spectral preference at 360, 420, and 480 nm, and T. vaporariorum at 320, 340, and 380 nm. The addition of LEDs to yellow sticky traps enhanced their capture efficiency for some key pests in commercial protected crop growing environments, and has the potential to enable pest detection at an early stage, consequently optimising the timing of pest management options.
2

Desenvolvimento do ciclo e desempenho agron?mico do mamoeiro sob cultivo org?nico em ambiente protegido. / Cycle development and agronomic performance of papaya under organic cultivation in protected environment.

Martelleto, Luiz Aur?lio Peres 19 January 2007 (has links)
Made available in DSpace on 2016-04-28T14:58:58Z (GMT). No. of bitstreams: 1 2007- Luiz Aurelio Peres Martelleto.pdf: 2127585 bytes, checksum: 81c879a6537f8e53170021781a03c57a (MD5) Previous issue date: 2007-01-19 / A study was conducted at the Integrated System of Agroecological Production (a Research Farm, located in Serop?dica, State of Rio de Janeiro), to evaluate the cycle development and the agronomic performance of papaya under organic management, comparing two ways of growing the plant (with and without trunk bifurcation) in three types of protected environment. Papaya seedlings, cv. Baixinho de Santa Am?lia ("Solo" group), were transplanted to contiguous structures as follows: (a) greenhouse (plastic covering), (b) shadowed greenhouse ('sombrite' net - 30%, over the plastic sheet), and (c) screenhouse ('sombrite' net - 30%, exclusively), side-by-side to an area for papaya cultivation under natural conditions. The greenhouse lateral and frontal parts were protected with anti-aphid screen. In these four treatments, 50% of the hermaphrodite plants were submitted to an incision of the apical bud, soon after sex determination. For a 12 months period of cultivation: temperature, relative air humidity and light radiation were measured in each environment. Regarding to development of papaya: plant height, basal trunk diameter, number of leaves per plant, foliar area, and periods of time to complete phases of the cycle were determined. A study of floral biology and of fruits characteristics also corried out. Cultural practices agreed with technical rules of organic agriculture. For comparisons among differents environments, the jointly experiment analysis" method was adopted. Trunk bifurcation reduced plant height thus extending the time period of papaya production cycle under covered environments. However, there was negative influence in number and average weight of harvested fruits. In the greenhouses (plastic and plastic plus sombrite coverings) there were increases with respect to: plant height, number of leaves, foliar area and time- life of leaves in the plant. In addition, there were reductions in the incidence of black spot (leaves and fruits) and of fruit skin freckles. In the shaded environments, percents of pentandric and carpeloid fruits were lower, opposite to that of estaminate flowers. In the screnhouse (only sombrite net), a decreased proportion of fruits reaching commercial standart occurred. In the greenhouse (plastic covering), other benefitial effects were noticed, such as: anticipation of flowering and fruit harvesting, due to the acceleration of fruit ripening in the plant. Although an increase in the number pentandric, carpeloid and deformed, fruits was observed cultivation in the greenhouse also induced a highly significant increment in yield of marketable fruits (around 67%) compared with the natural environment. The results obtained indicated potential for organic papaya cultivation under greenhouse conditions, as judging by the expressive gain in productivity and plant health, besides the acceleration of the cycle. / O estudo foi conduzido no Sistema Integrado de Produ??o Agroecol?gica - S.I.P.A. (Fazendinha Agroecol?gica Km 47), situado em Serop?dica,RJ, tendo como objetivos acompanhar o desenvolvimento do ciclo e avaliar o desempenho agron?mico do mamoeiro sob manejo org?nico, comparando duas formas de condu??o da planta (com e sem bifurca??o do tronco), em ambiente natural e em tr?s tipos de ambiente protegido. Para tanto, mudas de mamoeiro da cultivar Baixinho de Santa Am?lia, grupo Solo , foram transplantadas para tr?s estruturas cont?guas: (a) estufa (cobertura de pl?stico), (b) estufa sombreada (cobertura adicional de sombrite 30% sobre o pl?stico) e (c) telado (cobertura de sombrite 30%); estabelecendo-se, ao lado, uma ?rea de cultivo em ambiente natural. Nas estufas (a e b), as laterais e frentes foram revestidas com tela anti-af?dica. Nesses quatro tratamentos, 50% das plantas hermafroditas tiveram o tronco bifurcado por meio de incis?o da gema apical, logo ap?s a determina??o do sexo. Registraram-se, ao longo de 12 meses de cultivo: temperatura, umidade relativa do ar e luminosidade em cada ambiente. Quanto ao desenvolvimento do mamoeiro: altura da planta, di?metro do tronco, n?veis de enfolhamento, ?rea foliar e per?odos de tempo para cumprimento de fases do ciclo, foram monitorados. Realizou-se, ainda, estudo da biologia floral e das caracter?sticas dos frutos produzidos. Os tratos culturais empregados obedeceram ?s normas t?cnicas da produ??o org?nica. Para compara??o entre ambientes de cultivo, adotou-se o m?todo da an?lise conjunta de experimentos . A bifurca??o do tronco reduziu a altura da planta prolongando o cultivo do mamoeiro nos ambientes cobertos. No entanto, teve influ?ncia negativa no n?mero e no peso m?dio dos frutos. Nas estufas (coberturas de pl?stico e de pl?stico mais sombrite) houve aumentos em rela??o a: altura da planta, n?vel de enfolhamento, ?rea foliar e sobrevida das folhas. Por outro lado, ocorreram redu??es da incid?ncia da var?ola (folhas e frutos) e da mancha fisiol?gica nos frutos. Nos ambientes sombreados, os percentuais de frutos pent?ndricos e carpel?ides foram mais baixos, ao contr?rio de flores estaminadas. No telado, registrou-se menor propor??o de frutos atingindo padr?o comercial. Na estufa, ocorreram benef?cios do ponto de vista agron?mico, destacando-se: antecipa??o do florescimento e do in?cio da colheita, al?m da acelera??o do amadurecimento dos frutos na planta. Embora tenha havido aumento do n?mero de frutos pent?ndricos, carpel?ides e aplastados, o cultivo na estufa proporcionou aumento altamente significativo da produ??o de frutos comercializ?veis (em torno de 67%) em compara??o ao ambiente natural. Os resultados obtidos indicaram potencial para o cultivo org?nico do mamoeiro sob condi??es de estufa, em fun??o dos ganhos expressivos de produtividade e sanidade, al?m de precocidade e acelera??o da colheita.

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